CBC is a component within the Lighthouse Studio of interviewing products. CBC is used for conducting Choice-Based Conjoint (CBC) studies over the web, in "CAPI" interviewing mode where devices do not always have internet access, or via paper-and-pencil questionnaires. CBC questions are usually integrated within a longer questionnaire that includes other standard survey questions. The number of additional questions that can be added depends on your license. A CBC study can include additional standard survey questions that collect up to 50 data fields. An unlimited number of additional questions can be used if the largest Lighthouse interviewing license is acquired.
CBC studies are used for learning about respondents' preferences for the combinations of features that make up products or services. CBC analysis can help with (among other things) product design, line extensions, pricing research, and market segmentation. There are also numerous opportunities for using CBC in modeling economics and healthcare choices.
A sample CBC questionnaire (cbc.ssi) and supporting files are available in the \Samples folder within your Lighthouse Studio installation. You can easily access this example study by clicking Help | Sample Studies. This questionnaire lets you see an example of a CBC survey and investigate how it is set up.
If you know a little HTML (which is not necessary to use CBC), you can employ some "tricks" to help you customize the look of your survey beyond the standard options provided by the software. By opening the sample study and looking at the settings and text we've used, you can become familiar with some of the possibilities.
Using CBC requires the following skills and knowledge base:
•The analyst managing the survey should know the basics of conjoint analysis, including defining attributes and levels properly, correctly phrasing the questionnaire text and response scales, interpreting the part-worth utilities, and running simulations. It is not necessary to be a statistician to use our software effectively, but knowledge of basic statistics for market research is highly recommended.
•The questionnaire is first composed locally on a PC running under Windows 7 (or later). The individual inputting/formatting the survey should have working knowledge of standard Windows applications such as word processing, Web browsers and/or spreadsheets. Though it is not necessary, some knowledge of HTML is valuable.
Steps in Conducting a CBC Study
1) Formulate attributes and levels and type them into the CBC interface.
2) Make decisions regarding your study design: decide how many product concepts to display per choice question (task), whether to include a "None" option, and how many choice tasks to field in your study. Using the point-and-click CBC interface, add those CBC questions to your Lighthouse study.
3) Test your questionnaire in preview mode, by using the Local Test Server included in Lighthouse Studio, or by uploading the files to your Web server. Make modifications and re-test.
4) Decide how many unique versions of the CBC questionnaire to use in your overall design (default is 300). If using paper-and-pencil data collection, it is common to use a few to a dozen design versions. Generate the design. Using the Test Design module, test the CBC design to make sure the design is efficient to estimate the part-worth utilities (main effects).
5) If using web-based data collection, upload your study to an Internet server and continue testing--by yourself, with colleagues, and later preferably with a small number of pilot respondents. Receive feedback from colleagues and pilot respondents. Examine the test data to make sure all data are being stored properly using the Admin Module and by downloading the data to your hard drive. Estimate part-worth utilities for the test data using logit or HB (hierarchical Bayes) to see that the results seem to have face validity.
6) After ensuring that your CBC questionnaire works properly, that the data are being stored correctly, and that your design is not deficient, invite respondents to take the survey.
7) Monitor the data collection using the Admin Module. Download the data, examine the utility scores for your attribute levels (options include Counts, Logit, Latent Class, and HB) and then use the market simulator for running base case and what-if simulation scenarios.